As the World Wide Web has emerged as a major research tool across all fields of study, the concept of metadata has become a crucial topic. Metadata, which can be broadly defined as “data about data,” refers to the searchable definitions used to locate information. This issue is particularly relevant to searches on the Web, where metatags may determine the ease with which a particular Web site is located by searchers. Metadata that are embedded with content is called embedded metadata. A data repository typically stores the metadata detached from the data.
Results obtained from search engine queries are limited to metadata information stored in a data repository, referred to as an index. With respect to media files or streams, the metadata information that describes the audio content or the video content is typically limited to information provided by the content publisher. For example, the metadata information associated with audio/video podcasts generally consists of a URL link to the podcast, title, and a brief summary of its content. If this limited information fails to satisfy a search query, the search engine is not likely to provide the corresponding audio/video podcast as a search result even if the actual content of the audio/video podcast satisfies the query.